Two-dimensional profile detection system

• US 5,182,614 A
• Filed: 01/31/1991
• Issued: 01/26/1993
• Est. Priority Date: 01/31/1991
• Status: Expired due to Fees

• Current Assignee: Snap-On Technologies Incorporated (Snap-On Incorporated)
• Original Assignee: FMC Corporation
• Inventors: Lill, Melvin H.
• Primary Examiner(s): Rosenberger, Richard A.
• Application Number:
  US07/648,066
• Time in Patent Office: 726 Days
• Field of Search: 356/376
• US Class Current: 356/610
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50

Abstract

The invention disclosed herein relates to a detection system for a profile line on an observed body which uses a linear array of sequentially energized energy beam emitters to project beams toward the body. Reflections of the beams are detected by a linear array of energy beam receivers which monitor wedge shaped sectors within a field of view. The known sequence of beam projection and the known sector of reception of reflected beams are used to identify points in space on the profile line.

Claims

1. A system for detecting a two dimensional profile on a body within a field of view, comprising

a plurality of energy emission means for emitting a plurality of energy emission beams substantially within a plane containing the two dimensional profile,

projector lens means interposed between said plurality of energy emission means and the body for focusing the beams in a known fan-like pattern having known diverging projection directions within the field of view,

excitation means for individually exiting said plurality of energy emission means in predetermined sequence and for providing a plurality of excitation indicative signals corresponding thereto, said energy beams being reflected by the body upon impingement thereon,

a plurality of detector means for receiving said reflected energy beams for each defining discrete field depth sectors within the field of view and for individually receiving reflected energy beams within one of said field depth sectors and providing a plurality of discrete sector signals corresponding to ones of said received reflected energy beams,

detector lens means interposed between the body and said plurality of detector means for focusing reflected energy beams within the field of view on said plurality of detector means, and

means for receiving said plurality of discrete sector signals and said plurality of excitation indicative signals and for indicating a locus of points having discrete sector and known projection direction characteristics along the body profile within the energy beam emission plane.

2. A profile detection system as in claim 1 wherein said plurality of energy emission means comprises an array of light emitting diodes arranged in a linear array.

3. A profile detection system as in claim 1 wherein said plurality of detector means comprises a line of adjacently mounted photo diodes, the intersections of the known projection directions of said known fan-like pattern of energy emission beams and said field depth sectors defining said locus of points.

4. A two dimensional profile detection apparatus for detecting a body profile within a plane contained in a field of view, comprising

a plurality of energy emitting means arranged in linear array and projecting a plurality of individual energy beams within the plane containing the body profile toward the body when energized,

emitter lens means for focusing said individual energy beams and for directing said beams in a plurality of unique known directions within a fan-like pattern within the field of view,

control means for energizing said plurality of energy emitting means in predetermined sequence and for providing a plurality of individual beam energizing signals corresponding to ones of said energized emitting means, whereby said energy beams impinge said body and are reflected therefrom within said field of view,

a plurality of detector means arranged in linear array exposed to the field of view and each individually exposed to a unique field depth sector within the field of view,

detector lens means interposed between the body and said plurality of detector means for focusing said individual energy beams reflected from the body onto said linear array of detector means, whereby one of said individual detector means within said plurality thereof which is impinged by one of said reflected individual energy beams from a unique field depth sector produces a discrete detector output signal, and

means for conditioning and identifying each of said discrete detector output signals to identify the individual energy beam unique known direction which is reflected from the body and the unique field depth sector from which it is received and for providing intersection data between said energy beams unique known directions and said unique field depth sectors, whereby a locus of points within the plane containing the body profile is identified.

5. A method of detecting a profile on a body within a plane situated within a field of view comprising the steps of

projecting a plurality of energy beams within the plane containing the profile toward the field of view from ones of an array of beam projectors in a fan like beam array having unique beam directions and in a predetermined projection sequence,

detecting the energy beams reflected from the surface of the body within the field of view with an array of beam detectors,

directing the reflected energy beams so that individual ones of the beam detectors in the array receive reflected beam energy from substantially only one field depth sector in the field of view, thereby providing a unique field depth detector output upon receipt of reflected beam energy,

identifying the projected beam which is reflected to produce the beam detector output by reference to the predetermined projection sequence, and

identifying the field depth sector of impingement within the field of view by reference to the output from the one impinged detector, whereby intersections between ones of said beams having a unique beam direction and ones of said field depth sectors provides a locus of points along the profile within the plane.

6. The method of claim 5 wherein the step of detecting with an array of beam detectors comprises the step of arraying the beam detectors in a straight line.